<template>
  <div id="message" v-scroll-bottom="sessions">
    <ul v-if="currentSession">
      <li v-for="(entry,index) in sessions[user.username+'#'+currentSession.username]" :key="index">
        <p class="time">
          <span>{{ entry.date | time }}</span>
        </p>
        <div class="main" :class="{self:entry.self}">
          <img class="avatar" :src="entry.self ? user.userFace : currentSession.userFace" alt />
          <div style="text-alin">
            <p class="text">{{ entry.content }}</p>
          </div>
        </div>
      </li>
    </ul>
  </div>
</template>

<script>
import { mapState } from 'vuex'

export default {
  name: 'message',
  data () {
    return {
      user: JSON.parse(window.sessionStorage.getItem('user'))
    }
  },
  computed: mapState([
    'sessions',
    'currentSession'
  ]),
  filters: {
    time (date) {
      if (date) {
        date = new Date(date)
      }
      return `${date.getHours()}:${date.getMinutes()}`
    }
  },
  directives: { /* 这个是vue的自定义指令,官方文档有详细说明 */
    // 发送消息后滚动到底部,这里无法使用原作者的方法，也未找到合理的方法解决，暂用setTimeout的方法模拟
    'scroll-bottom' (el) {
      // console.log(el.scrollTop);
      setTimeout(function () {
        el.scrollTop += 9999
      }, 1)
    }
  }
}
</script>

<style lang="scss" scoped>
#message {
  text-align: left;
  padding: 15px;
  max-height: 68%;
  overflow-y: scroll;

  ul {
    list-style-type: none;
    padding-left: 0px;

    li {
      margin-bottom: 15px;
    }
  }

  .time {
    text-align: center;
    margin: 7px 0;

    > span {
      display: inline-block;
      padding: 0 18px;
      font-size: 12px;
      color: #fff;
      background-color: #dcdcdc;
      border-radius: 2px;
    }
  }

  .main {
    .avatar {
      float: left;
      margin: 0 10px 0 0;
      border-radius: 3px;
      width: 30px;
      height: 30px;
    }

    .text {
      display: inline-block;
      padding: 0 10px;
      max-width: 80%;
      background-color: #fafafa;
      border-radius: 4px;
      line-height: 30px;
    }
  }

  .self {
    text-align: right;

    .avatar {
      float: right;
      margin: 0 0 0 10px;
      border-radius: 3px;
      width: 30px;
      height: 30px;
    }

    .text {
      display: inline-block;
      padding: 0 10px;
      max-width: 80%;
      background-color: #b2e281;
      border-radius: 4px;
      line-height: 30px;
    }
  }
}
</style>
